Methotrexate (MTX) is an antifolate and is used for the treatment of acute leukemia, malignant lymphoma and other diseases. It is also known as an immunosuppressive drug and is primarily used for preventing acute graft-versus-host reactions in bone marrow transplantation. Furthermore, administration of low doses of MTX is known to be effective for the treatment of rheumatoid arthritis.
However, MTX causes comparatively severe side effects such as hepatotoxicity and fibrosis in lungs, which are often problematic in its clinical use. Consequently, development of drugs are desired that have strong efficacy and minimal side effects.